Simultaneous elevation of the serum concentrations of vascular endothelial growth factor and interleukin‐6 as independent predictors of prognosis in aggressive non‐Hodgkin's lymphoma

Abstract
Therapeutic approaches for non-Hodgkin's lymphoma (NHL) are currently based on the International Prognostic Index (IPI). Research on biological prognostic factors has been actively pursued in recent years, with serum vascular endothelial growth factor (VEGF) and interleukin-6 (IL-6) being identified as prognostic factors for NHL. Here, we determined that serum VEGF and IL-6 levels are independent prognostic factors for aggressive lymphoma. Compared with normal controls, serum VEGF and IL-6 levels were significantly higher in patients with aggressive lymphoma or adult T-cell leukemia/lymphoma. Furthermore, overall and disease-free survival rates for patients with high levels of VEGF or IL-6 were significantly poorer than for patients with low levels. In addition, the prognosis for patients with high levels of both serum VEGF and IL-6 was significantly poorer than that for patients with high levels of either VEGF or IL-6 or with low levels of both VEGF and IL-6. Multivariate analyses of a variety of prognostic factors, including the five IPI factors, revealed that serum VEGF and IL-6 were both independent prognostic factors for overall survival of aggressive lymphoma. Therefore, a combination of VEGF and IL-6 represents a useful prognostic factor for aggressive lymphoma.